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Introduction: Human leukocyte antigen (HLA)‐B*5701 screening identifies patients at increased risk for abacavir (ABC) hypersensitivity reaction (HSR). Screening was adopted in GlaxoSmithKline and ViiV Healthcare clinical trials in 2007 and human immunodeficiency virus treatment guidelines in 2008. Company meta‐analyses of trials pre–HLA‐B*5701 screening reported HSR rates of 4–8%. We analyzed the effectiveness of HLA‐B*5701 screening on reducing HSR rates using clinical trial, Observational Pharmaco‐Epidemiology Research & Analysis (OPERA) cohort, and spontaneous reporting data. Methods: A meta‐analysis examined 12 trials in 3063 HLA‐B*5701–negative patients receiving an ABC‐containing regimen from April 9, 2007, to September 22, 2015. Potential cases were identified using prespecified Medical Dictionary for Regulatory Activities (MedDRA) preferred terms (drug hypersensitivity, hypersensitivity, anaphylactic reaction, anaphylaxis) and adjudicated against a Company ABC HSR case definition. Investigator‐diagnosed cases were identified and rates were calculated. In the OPERA cohort, 9619 patients initiating their first ABC‐containing regimen from January 1, 1999, to January 1, 2016, were identified. Patients were observed from regimen start until the earliest‐following censoring event: ABC discontinuation, loss to follow‐up, death, or study end (July 31, 2016). OPERA physicians evaluated events against OPERA definitions for definite/probable cases of ABC HSR; rates were calculated pre‐ and post‐2008. The Company case definition was used to identify spontaneously reported cases for four marketed ABC‐containing products; reporting rates were calculated using estimated exposure from sales data, through December 31, 2016. Results: Suspected ABC HSR rates were 1.3% or less in the meta‐analysis. In the OPERA cohort, the rate was 0.4% among patients initiating ABC post‐2008 versus 1.3% pre‐2008 (p<0.0001). Spontaneous reporting rates were low post‐2008 (54 to 22 cases per 100,000 patient‐years exposure [PYE]) versus pre‐2008 (618 to 55 cases per 100,000 PYE). Conclusions: Clinically suspected ABC HSR rates were 1.3% or less in HLA‐B*5701–negative patients. Recognizing their limitations, data from the OPERA cohort and spontaneous reporting indicate that HLA‐B*5701 screening has reduced reporting rates of suspected HSR in clinical practice. Where screening for HLA‐B*5701 is standard care, patients should be confirmed negative for this allele before starting ABC treatment. [ABSTRACT FROM AUTHOR]

Background Some observational studies and randomized controlled trials (RCTs) have suggested an association between abacavir (ABC) use and myocardial infarction (MI), whereas others have not. Methods This pooled analysis of 66 phase II–IV RCTs estimates exposure-adjusted incidence rates (IRs) and relative rates (RRs) of MI and cardiovascular events (CVEs) in participants receiving ABC- and non-ABC-containing combination antiretroviral therapy (cART). The primary analysis of MI included ABC-randomized trials with ≥48-week follow-up. Sensitivity analyses of MI and CVEs included non-ABC-randomized and <48-week follow-up trials. Results In 66 clinical trials, 13 119 adults (75% male, aged 18–85 years) were on ABC-containing cART and 7350 were not. Exposure-adjusted IR for MI was 1.5 per 1000 person-years (PY; 95% confidence interval [CI], 0.67–3.34) in the ABC-exposed group and 2.18 per 1000 PY (95% CI, 1.09–4.40) in the unexposed group. The IR for CVEs was 2.9 per 1000 PY (95% CI, 2.09–4.02) in the exposed group and 4.69 per 1000 PY (95% CI, 3.40–6.47) in the unexposed group with studies of ≥48 weeks of follow-up, with an RR of 0.62 (95% CI, 0.39–0.98). The inclusion of nonrandomized and shorter-duration trials did not significantly change the RR for MI or coronary artery disease. Conclusions This pooled analysis found comparable IRs for MI and CVEs among ABC-exposed and -unexposed participants, suggesting no increased risk for MI or CVEs following ABC exposure in a clinical trial population. Modifiable risk factors for MI and CVEs should be addressed when prescribing ART. [ABSTRACT FROM AUTHOR]